I'm facing a very annoying error but I'm unable to find an answer for it.


  • Using Metamask, having accounts in eth Popsten with ETH coins, bsc and matic with coins
  • I'm using just a simple ProvableAPI example script (LINK) that works if I chose the ETH network, I deploy the contact and then I call the function
  • However, when I try the same approach in Binance Smart Chain or MATIC networks fails with "Gas estimation errored"

The message is as follows: Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending? Internal JSON-RPC error. { "code": -32000, "message": "execution reverted" }

I'm guessing might be a problem in the configuration? or in the gas setup? (I'm using the default parameters)

pragma solidity ^0.4.22;
import "github.com/provable-things/ethereum-api/provableAPI_0.4.25.sol";

contract ExampleContract is usingProvable {

   string public ETHUSD;
   event LogConstructorInitiated(string nextStep);
   event LogPriceUpdated(string price);
   event LogNewProvableQuery(string description);

   function ExampleContract() payable {
       LogConstructorInitiated("Constructor was initiated. Call 'updatePrice()' to send the Provable Query.");

   function __callback(bytes32 myid, string result) {
       if (msg.sender != provable_cbAddress()) revert();
       ETHUSD = result;

   function updatePrice() payable {
       if (provable_getPrice("URL") > this.balance) {
           LogNewProvableQuery("Provable query was NOT sent, please add some ETH to cover for the query fee");
       } else {
           LogNewProvableQuery("Provable query was sent, standing by for the answer..");
           provable_query("URL", "json(https://api.pro.coinbase.com/products/ETH-USD/ticker).price");

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